Annual report pursuant to Section 13 and 15(d)

Organization - Additional Information (Details)

v3.8.0.1
Organization - Additional Information (Details)
12 Months Ended
Dec. 31, 2017
investment_fund
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Power purchase or lease agreement term 20 years
Number of types of investment funds used by the company 3